Solid bifocal lens.



O. W. GONNER.

SOLID BIFOGAL LENS.

APPLIOATION IILBD 0012s, 1902.

932,965, Patented Aug.31,1909.

2 SHEETS-SHEET 2.

Quvcnl'oz charleswconner.

-UNITED ratr NT OFFICE. a

CHARLES W. CONNER, F INDIANAPOLIS, INDIANA.

SOLID iairooAi. I'ZENs.

To all whom alt may concern;

Be it. known thati, UnimLnsNV CONN'ER, a citizen of. the United btates, residing at Indianapolis, in the county of Marion and State of Indiana, have invented certain new and useful Improvements in Solid Bifocal Lenses, of which the following is a specification. V

The object of this invention is to provide a bifocal lens-made from a single piece of glass having on one face thereof two visual surfaces of different dioptrics, the upper surface being the distance field and the lower surface being the near orreading field, and having an arched division separating the two fields, the lens at the curved line of joinder of the two fields having uniform thickness through both fields. Such a bifocal lens avoids the ditliculties and the expense of bifocal lenses formed of two or more pieces of glass, and it also presents a smooth surface at the junction or division between the two fields, so as to render the lens practically free at that effects.

The nature of the invention will be undersiltood from the following description and c aim.

point from any prismatic In the drawings Figure 1 is a central sectional View of a lano-concave lens having a plane surface conjoining with the concave surface. Fig. .2 .is a similar sectionof a lens produced from the lens shown in Fig. 1, the plane-lens surface, which conjoins the, concave lens surface, being shown at the periphery of the'lens. Fig. 3 is a view-similar to Fig. 1 showing a concave surfacelor minus lens with a plus lens conjoining therewith. Fig. 4 is a sectional view of a lens cut from the lens shownin Fig. 3. Fig.- 5 is a view similar to Fig. 1 showing a convex or plus lens with a plano-lens surface conjoining therewith. Fig. 6 is a sectional view of a lens cut from the lens shown in Fig. 5. Fig. 7 is a view similar toFig. 1 showing a plus lens surface having a plus lens surface of different and reater curvature conjoining therewith. Fig. 8 is'a sectional view of a lens cut from the lens shown in Fig. 7. Fig. 9 is the same as Fig. 2 with" the unfinished side of the lens finished in the usual Way. Fig. 10 is a perspective view of the lens shown in Figs. 1, 2and 9, finished. Fig. 11 is a perspective view of the minor field of. the lens shown in Figs. 1, 2,9 and 10 broken away substantially at the junction Specification of Letters Patent. Patented Aug. 31, 1909. Application filed October 88, 1902. Serial No. 128,878. i

' between the two hclds Fig. 12 IS the same as Fig. 4. with the o )posing unfinishedside the lens ti-nishcdin the usual way. l i'g. 13 is a perspective view of the finished lens shown in. Figs: 3, 4- and 12. Fig. 14 isthe sanierus Fig.1) with the opposing unfinished side finished in the usual wa.y. Fig. 15 isia perspective view of the lens shown ,in Figs.

5 (3 and 14, finished, Fig. .I'U is the'sanie'as Fi 8 with the opposing or unfinished side finished in the isual way. Fig. 17 is a' perspective view of the lens shown in Figs. 7,

8 and 16 in finished form. Fig. 18 is a per spective View of the lens as shown in Fig. 16 with the minor field broken away substantially at the line of junction between "the two fields.

The drawings in several forms or blanks which said bifocal lens may assume in connection with an opposing plane surface, as the conformation of the opposing surface is immaterial to this invention, for the invention 'lies in the culiar relative positions of the two COIljOlllw The finished form of such lens is illustrated in the remaining figures in the drawings.

In Figs. 1, 2, 9, 10 and 11, 20 indicates the body ofthe lens, while 21 indicates a minus surface, and 22 indicatesv a planosurface conjoining therewith. The other Figs. 1 to 8 illustrate,

.80 ing lens surfaces on one side of the lens.

figures illustrate the other types of lenses,

in which the larger visual surface is marked 21 and the smaller surface 22 Figs. 1, 3, 5, and 7 illustrate blanks in which the surface 22 or 22 is central, and the surface 21 or 21 surrounds and is concentric with said surface 22 or 22%. By removing one side portion of each of said blanks, the lensv or blanks shown iii Figs. 2,

4, 6, and 8 result, the surface 22 losing atone margin of said lens or blank. This more fully appears in another application for Letters Patent of the UnitedSt-ates by me, Serial No. 153,697, filed April 21, 1903, for improvements in the method of producing bifocal lenses. .of the lens, as shown in Figs. 2, 4, 6 and 8, is ground or formed as desired, the finished lenses shownin Figs. 9, 10, 12, 13, 14, 15, 16 and 17 result. The finishing of the unfinished surfaces in said lenses, as shown in Figs. 2, 4, 6 and 8, is well understood in the art and may beiaccomplished by any desired means. In said finished lensest-he upper When the unfinished surface.

\ Nov. 20, 1906.

distance field, and the lcwer and smaller junction is of uniform thickness, whereby there 1s a smooth and even surface at the junction of the two fields and the division Es practically. free from any prismatic efects.

The lenses herein shown and described may beproduced in any desired manner or by any preferred means, one such means, however, being set forth in Letters Patent of the United States No.

What I claim as my invention and desire to secure by Letters Patent is:

836,486, granted A I v A bifocal lens cbm rising one plece of glass having an up er istancefield, a lower and smaller near eld, and en arched division separatingthe twofields, but the lens y In witness .w ereof I have hereunto, set my hand and seal, at Indianapolis, Indiana,

sand-nine hundred and two.. I

CHARLES w. CONNER. "|i,. s.]

this 20th day of Qctober, A. D. one them Witnesses I An'rnun Hoon, JAMns A. WALSII. 

